Born in Suwon, Gyeonggi Province, he was an aspiring singer in his adolescence and applied to the Department of Theater and Film in high school, but majored in dance following the denial of his initial application.

[2] He graduated from the institution and, for two years, served as a ballet instructor for rhythmic gymnasts Son Yeon-jae and Shin Soo-ji.

[6] After deliberating between a career in ballet and music, he decided to participate in the second season of the talent television series Superstar K.[2][7] Following his appearance on the show, he began receiving "love calls" from various entertainment companies, which he rejected for an opportunity to try out for Fly to the Sky's Hwanhee under H2 Media.

Upon failing the audition, he sat by a water purifier at the company's entrance and greeted staff for the following seven consecutive days to have them recognize his face.

[9] Kang made his acting debut along with his group in the film Shinokubo Story (2013), where he played one of five characters seeking to become "stars".

[11] Kang's musical style was influenced by Big Bang's Taeyang, JYJ's Kim Junsu, Chris Brown and Usher.

[13] The mini-album ranked at number 19 on Japan's national Oricon Albums Chart, selling 3,346 copies in its first week.